Control for presses



June 17, 1930. W, B, STUART 1,765,314

001111110111011 PRESSES Filed March 19, 1924 2 Sheet's-Sheet l June 17, 1930. w. B. STUART 1,765,314

CONTROL FOR PRESSES Filed March 19, 1924 2 suyas-sheet 2 "II" 208 206 LLLLQN l O* i f l f I LJ' ll ,(:d/

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i :l r1 a 'n 1w' Patented June 17, 1930 PAT-ENT orricEy f WILLIAM B. STUART, on TAMPA, rLonrDA, Assis-Non TO'TI-IE'INTERNATIONAL PAVE- MENT ooMPANY, oF HARTFORD, CQNNECTICUTQA oomonATroNk on CONNECTICUT CONTROL ToRvPnEssn's Application mea March 19, 1924. "serial No. 700,312.

formy of one embodiment ofvmy invention Figure 1 is a plan view ofa portion of a press; l y M j Fig. 2 is a side elevation of the parts4 shown "inFig.1;, v

Fig. 3 is a view similar ,to Fig. 2, but showing additional portions of the press mechanism,4 being partly in vertical longitudinal SeCtQn; t l Y' y.

FigA is a view llike Fig. 3,`but showing the relation of the parts during adifferent portion of their cycle of operation; and Fig. 5 is a section on th linef of Fig. 2. Referring to the drawings andtofthe pre'- ferred form of my invention selected for i illustrative purposes, I haveL shown my improved control mechanism associated with a press which may be thatA shown in United States vLetters vPatent No 1,003,561,issued l September'19,.1911, to International Pavement Company, assignee of George E. Whitn'ey,"and forpurposes of yclarity Il have, so .far as applicable, Tadopted theinumeralsl of the drawings of said patentto the drawingsoi' the presentiap'plication.. .fl The press shown in saidpatent can operate 'atvery high speed considering the high pressures applied tothe moldedblocks produced `thereby yandthe weight ofthe moving parts thereof, but at` y the higher' jspeeds certain parts, becauseof their' weight andfspeediof movement, become Vspeed-limiting 4factors. It is to these pr'rts thatI have-applied my improvedrcontrohy Y Inthe press illustrated,@liquidin'` a hy- 'draulic cylinder 1 actuates a ram2 constituting'a .preferrediform of,v compressing in- 'strum'entalityl carrying an ej ecting head guide 22 which guides the ejecting head 23 to fvhich ,is attached the,r mold plunger and plunger cap 26. i

Thecycle of ,v ,5,0 s'trumentality vtypified he yranfr2 from @pee-ecn 'this plunger wp. includes lmovementby thel compressing in-l filling position I(Fig. 3) to an intermediate position where the. material isv compressed under the' desired pressure against` the pressure block 21 (which is above the mold in pressing position), a slight downward movementmto relieve the pressure on the plunger cap during the uncovering of, thermold, followed by. ejecting movementl of A,the plunger cap 'l and associatedfpa-rts4 to. the. position shown in Fig. @this position being maintaineduntil thebloek isiswept from'above the mold by thel forward .movement ofthe sliding head 14, which carries the pressure block the filling neck 15. y The-eject'- 4movement before described is actuated Y crank lever 134 fulcrumed at'185'and adapted to .move the ejecting head 23 without correspondingV -movement of lthe ejecting head `guide22` or of the ram I2. i

. yAfter the block has been swept from the top' ofthel mold plungen'the latter isperfmitted to drop by gravity under the control of the cam 66, this being the mold filling movement.` v

l The ejecting hea'd'23, plunger andplunger cap 26 are of 'considerable'weighu and the proportion of the cycle of operation allowed `for ejectmg Vand filling movement by the'cam A6.6 is'necessarily rather small. Therefore the plunger cap'. and associated parts'fmay be moved so quickly during ejecting `movement that,` the top ofthe plunger cap may, by ,the

momentum of the parts, be projected beyond v jthe upper surface of the mold and be struck the cam 66 operatingl through the bell bythe sliding head during its movement from ejectinginto mold filling' positions. Even `asidefrom this possible accident, Y,the strain and jar on the press incidental to rapid movement of the ejecting head is likely to result 'in ward'A mold filling movement' than on the upward ejectingor mold emptying movement.

. To minimize the ldifliculti'es described, VI

Ahave lprovided deceleration means operativelyv .connected'tothe mold plunger 26`by attachment` tothe ejecting head 23,' which, vin `the being 'rigidly connected thereto.

. .9.0 damage, though to a less degree on the down- The deceleration means preferably includes, as illustrated, dash pot means and approprijate connections, the dash pot means preferably including', as illustrated, a cylinder V201, which is mounted to rock about av fulcrum 202, Vand'which contains a piston 203 connected to a piston rod aL passing through a suitable stuffing boX 205- The connections may include a lever 206connected at one end to the piston rod 204i, connected at its center considerably greater than the travel of the ejecting head 23 and associated parts.l The preferred lever or link connection permits travel in a straight line of the connection 207 between the lever 206 and the ejecting head 23,

the fulcrum 208 being oscillatory about the` axis-21,0 of the link 209, and the'cylinder 201 being mounted lfor oscillation about the axis 202, which maybe connected to the hydraulic VVcylinder 1 or 'otherfstationary part of the press. The cylinder`201 is filled with appropriate fluid, preferably a liquid havingl lubrieating-qualities, and 'connection between the opposite ends of the cylinder is effected through by-pass means typified by the ports 212, 213'connected by a conduit 214 in which areV preferably interposed valve means 215, 216 controlling the effective area of the ports 212 and 213 respectively.V Supplemental by- V 4() pass means effective during the mid-portion ofthe stroke ofthe piston 203 is provided in Y the Vpreferred form of my, invention illustrated, such supplemental by-passV means taking the lforni of a plurality of elongated depressions 220 on the inner wall of the cylinder 201, extending longitudinally thereof and 4adapted Vat. and'near mid-stroke of the' piston l2031to permit relatively free flow of liquid thereby.` This supplemental byfpass means becomes ineffective as the plunger 26 and ejecting head approach the end of the ejecting stroke and also, in thev preferred embodir ment of my invention illustrated, as the end Vofthe mold filling stroke is approached. Duringa portion of :the stroke the portl 221 `adjacentthe longitudinal centreof the cylinder 201permits relatively rapid escapey of the liquid'in front of the piston 203,'such :liquid either flowing to the opposite. side of the piston 203, or, if the valve 222 is open,-

, portions thereof may flow to the reservoir 223'vcontaining a replenishing supply of the Y*liquid and preferably held stationary, being kconnected tothe oscillatory ycylinder by a iiexible conduit typified bythe hose 224.v Y Y Y 'ports 212 Vand 221.

vmeans of relatively Vlarge The valves 215 and 216 may be regulated to suit the speed of operation of the press and the valve222 may be `entirely closed or opened to the desired extent, ythis depending on the supply of liquid in the cylinder and also onthespeed of operation of the press.. 'Assuming the parts to be in the position shown in F ig. 3 with the mold filled, the compressing instrumentalities typified by the ram 2 willforce the ejecting head 28 and the mold plunger 26 upwardly until the material in t-he mold is compressed to the desired eX tent against the pressure block 21. During this movement, Ythe piston 203 will have advanced in the cylinder 201without substani tial opposition from the liquid in advance thereof which is free to pass out through the The pressure on the molded block is then relieved, the pressure block 2l moved to the position Vshown in Fig. l 4, permitting elevation of the plunger cap'26 and associated ejecting head by the ejecting' cam 66 to the position illustrated where'the i molded block is entirely out of the moldand in` position to be swept forward l(to the left as viewed in Fig. 4) until the mold-filling neck is above the mold. At this time the cam -66 permitsthe mold plunger andfassociated ,parts to drop, iilling the vmold with uncompressed material froin the neck 15. Toward the end .of this downwardV movement, the deceleration means functionsto cushion the drop of the parts, relieving the impact on the-feed controlling mechanism, Where such Vis used as illustrated in thel/Vhitney Patent f1.0()

No. 1,003,561, or on theram or compressing -means, where the liquidV content yof the hydraulic cylinder is varied to control4 the amount of drop of the parts. Y

' Referring now to the detail of the cylinder-5105 201, this is preferably Vas illustrated constructed with an inner kslotted sleeveproviding the ports 220 and with a Y inder wall exterior to said` site Lsaid slots 220. yThis does not extend entirely around tlie'cylinder, the cylinder wall preferably fitting relatively closely to the slot-ted sleeve where the central sleeve andV oppo'.`

port 221 is provided.

While I have described and illustrated the i preferred form of my invention in detail, it

recess preferably I recess inthe cylat that portion will be understood that I have done'so for purposes of clarilication'and not for pur*- poses of limitation, and that major changes involvingv omission, substitution, reversal and alteration of parts maybe made without departing from the which is best defined in the following claims.

scope of Y'my4 invention,

' Claims:V f" 1.- `A dash ofthe mold plunger of a potY for controlling the movement` V press comprising,

in combination, a cylinder, a piston therein',

said cylinder provided with by-pass conduit effective' crosssectional area 'for the portion of said cyliniso der intermediate its length, conduit means of relatively small effective cross-sectional area connecting opposite end portions of said cylinder, and a liquid reservoir for the cushioning fluid of said dash pot connected to said first mentioned conduit means.

2. A dash pot for controlling the movement of the mold plunger. of a press comprising, in combination, a cylinder, a piston therein, said cylinder provided With by-pass conduit means of relatively large effective cross-sectional area for the portion of said cylinder intermediate its length, conduit means of relatively small effective crosssectional area connecting the opposite end portions of said cylinder, a liquid reservoir for the cushioning fluid of said dash pot, and conduit means connecting said two first mentioned conduit means with each other and with said reservoir.

In testimony whereof, I have signed my name to this specification.

WILLIAM B. STUART. 

